When should I change spark plugs to ensure my vehicle operates at its optimal performance? Is there a specific mileage I should adhere to, or perhaps certain symptoms that indicate their decline? How do the driving conditions I regularly encounter factor into this? For instance, does frequent short-distance travel necessitate more regular replacements than long highway commutes? Moreover, are there different recommendations based on the type of spark plugs installed, such as iridium versus copper? As I ponder the implications of delayed changes, I wonder: might I be risking not only fuel efficiency but also engine health? What are the telltale signs that could suggest a spark plug has reached the end of its life—misfires, reduced acceleration, or a decline in fuel economy? The quest for understanding the nuances surrounding spark plug maintenance is quite compelling, isn’t it? Ultimately, how do I decipher the right time for such an essential automotive task?